Create an attachment for a block response

children Array (max depth)

detail Integer (max depth)

format Integer (max depth)

mode String (max depth)

style String (max depth)

text String (max depth)

type String (max depth)

mentionName String (max depth)

isUnlinked Boolean (max depth)

rel String (max depth)

target String (max depth)

title String (max depth)

url String (max depth)

direction String (max depth)

indent Integer (max depth)

version Integer (max depth)

checked Boolean (max depth)

value Integer (max depth)

language String (max depth)